1. Field of the Invention
The present invention relates to hand tools, and more particularly to wrenches of the type known as open end. The novel wrench can drive many different sized fasteners by a single tool with ratcheting action, and can do so in two opposite directions. The present invention finds application in any field wherein hexagonal or similar headed fasteners are employed to assemble machines, furnishings, and objects of all types.
2. Description of the Prior Art
Hand wrenches for tightening and slackening threaded fasteners having polygonal heads are old and well known. These wrenches have made the use of such fasteners quite practical, since they readily enable necessary force to tighten and slacken fasteners. Varieties of wrenches include two headed open end wrenches typically formed from a single piece of steel. Open end wrenches have the advantage of lacking relatively movable parts. However, certain minor yet annoying deficiencies in the use of wrenches remain. One deficiency is that each head of most wrenches is configured to engage only one size fastener head. Since heads vary in size, usually in proportion to shank size, mechanics and craftsmen are usually obliged to have available an extensive plurality of wrenches to assure possessing a wrench suitable for each fastener head size frequently encountered.
A second problem frequently encountered in utilizing hand wrenches is their propensity to deform corners or apices formed at the juncture of two flat facets of the polygonal fastener head or nut. Frequently, deformation takes the form of rounding of the usually sharp line of intersection of two flat facets. In some cases, plastic deformation results in a distortion of a hexagonal or other polygonal configuration. In this case, an originally flat facet may bulge to the extent that the head of the fastener does not conform to a tool having a polygonal opening configured to receive the head of the fastener.
Box and ratchet wrenches apply a significant portion of force at the apices of the fastener head. Therefore, likelihood of rounding and deformation is significant. Simultaneously, if a fastener head has been deformed, a wrench may lose its ability to turn that fastener. The fastener may become useless, and if deformed in the installed, tightened condition, may prevent ready disassembly of the article to which it is fastened.
Another aspect in which hand wrenches are deficient is that because many fasteners require a large number of rotations of their threaded shanks to fully install and remove, an open end wrench is frequently removed from engagement with the fastener head and replaced thereon in an advantageous position to turn the fastener. The effort of frequently removing and replacing an open end wrench is laborious in that it noticeably increases the amount of time to install and remove fasteners compared to the use of ratchet action wrenches which do not need to be removed from engagement with the head.
The prior art has sought to improve hand wrenches in various ways. U.S. Pat. No. 2,671,368, issued to Fritz Diebold on Mar. 9, 1954, describes a wrench which can engage a plurality of fastener sizes, albeit only one at a time. This alleviates the necessity of possessing many wrenches. The wrench of Diebold also imposes force on flat facets of the fastener head between the apices thereof, thereby reducing likelihood of damage to fastener heads. However, the wrench of Diebold does not provide ratchet action, as can the present invention.
U.S. Pat. No. 1,479,772, issued to Walter Herbert Cook on Jan. 1, 1924, describes an open end wrench which provides ratcheting action, and can engage selectively any one of several nominal sizes with one wrench head. However, the wrench of Cook cannot apply torque to a polygonal fastener head only at the flat surfaces, while sparing the apices of the head from potentially deforming force.
U.S. Pat. No. 999,968, issued to Edwin A. Denham on Aug. 11, 1911, illustrates a wrench which accepts plural fastener sizes, which provides ratcheting action, and which applies torque to the flat facets of polygonal heads of fasteners. However, cooperation between the wrench head of Denham and a polygonal fastener is such that the fastener fits perfectly into the wrench, as illustrated in FIGS. 5, 6, and 7 in Denham. By contrast, adjacent flat surfaces of the novel wrench are arranged at an angle which prevents the facets of the wrench from abutting in flush contact with the wrench. A space or gap is created which accommodates potential deformation of the fastener in the present invention. This feature is absent in Denham.
U.S. Pat. Nos. 446,324 and 463,137, issued to Daniel H. Carpenter on Feb. 10, 1891, and Nov. 17, 1891, respectively, illustrate wrenches which receive plural fasteners, which ratchet, and which apply torque to facets of the fastener. However, unlike the present invention, there is no abutment of flat surfaces of both the wrench and of the fastener. Also, the wrenches of Carpenter do not provide the amount of accommodation of deformation of the fastener, as seen in the present invention.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.